Glyphosate, the active ingredient of Monsanto's RoundUp, is the most commonly used pesticide active ingredient in the U.S. From the product's beginnings back in the 1970s, it's been touted as a relatively safe, non-toxic chemical.

But the use of glyphosate has surged dramatically since the 1990s, when genetically engineered (GE) "RoundUp Ready" corn and soybean crops were introduced.This intensive usage raises an important and increasingly urgent question: have the human health and environmental impacts of glyphosate been carefully and exhaustively evaluated? What do we know and what don't we?

The little herbicide that could. That's what comes to mind as EPA proposes to up the residue levels of RoundUp allowed on food — despite a fresh round of studies pointing to possible human health effects from exposure.

The latest science examines links between Monsanto's flagship product and endocrine disruption, including a laboratory study that suggests an effect on cells similar to that of estrogen — a hormone that plays a role in stimulating breast cancer. PAN scientists are taking a careful look at these findings; given the widespread use of RoundUp (more than 180 million pounds every year) the public health implications could be dramatic.

A new study supports earlier findings that Monsanto’s biggest selling weedkiller may actually be harming crop production by increasing the incidence of fungal root disease. This could be why the "RoundUp-ready" corn and soybeans that Monsanto has engineered to be used with the herbicide have failed to deliver promised yields.

Add this to recent stories of RoundUp’s ubiquitous presence, concerns of serious health effects such as birth defects, and the creation of superweeds (as RoundUp resistance spreads from engineered crops to weeds) — you'd think this would be the final nail in RoundUp’s coffin, right? Not quite, but we're keeping the pressure on.

Like many people, I once believed in the safety of RoundUp. Back in the 1980s when I was a young graduate student in ecology, it was the “safe” herbicide of choice for clearing weeds from study plots.

Monsanto would like us to continue to believe their flagship product is safe, but the data are increasingly saying otherwise. The latest? Widespread exposure is a near certainty, since RoundUp — now linked to birth defects — shows up regularly in our water and air.

In some circles, it would be called a bribe, at best. Evidence revealed last week shows that Monsanto's former Chief Financial Officer admitted that the agrichemical corporation planned to spend $150 million in cash and trade incentives in Latin America, North America and Europe to spur the uptake of the pesticide glyphosate, better known as RoundUp. $150 million is no small change — and surely that's not all that's been spent.

The news came to light last week as part of an investigation by the U.S. Securities and Exchange Commission. Sadly, small farmers around the world know all too well the carrot and stick approaches that Monsanto and other pesticide giants use to lure farmers (and nations) toward industrial agriculture and onto the pesticide treadmill.

An international team of highly respected scientists has just released a stunning report, Roundup and Birth Defects, proving that Monsanto and industry regulators have known for decades that Monsanto’s top-selling weedkiller, Roundup, causes birth defects in laboratory animals.

On Feb. 4, USDA announced a “partial deregulation” of Monsanto’s genetically engineered sugar beets to allow planting in 2011. The move came despite a December federal court decision in which the judge ordered that GE beets already planted to produce seed “shall be removed from the ground”. USDA has defied the court on behalf of Monsanto before.

On January 27, Secretary of Agriculture Thomas Vilsack announced the USDA's decision to de-regulate Monsanto’s genetically engineered (GE) alfalfa, allowing it to be grown anywhere and placing both organic and conventional farmers at risk. “We in the farm sector are dissatisfied but not surprised at the lack of courage from USDA to stop Roundup Ready alfalfa and defend family farmers,” said Pat Trask, a conventional alfalfa grower and plaintiff in litigation to prevent planting of GE alfalfa.